Carburetor constant level device



Jan. 7, 1958 J. T. w. MOSELEY E AL 2,313,379

CARBURETOR CONSTANT LEVEL DEVICE Filed Oct. 25, 1952 sheets sheet l L m EN 24 gvwn 22 will Q 25 II a E1 )23 EIIA'EHI \v 117 fink 57 INVENTORS.

T. W. M O S E L EY D A.

H H. HERRON AT TOR NEY CARLSON Jan. 7, 1958 .1. T. w. MOSELEY T A 2,818,879

CARBURETOR CONSTANT LEVEL DEVICE -2 Sheets-Sheet 2 Filed Oct. 23. 1952 lllllll FIG.5.

JAMES INVENTORS. T. W. M O 8 EL EY D HAROL ACARLSON RALPH HERRON fifi ydfi ,4 ("A WW7 ATTORNEY United States Patent CARBURETOR CONSTANT LEVEL DEVICE James T. W. Moseley, Richmond Heights, Harold A. Carl'-v son, Brentwood, and Ralph H. Herron, Normandy, Mo., assignors, by mesne assignments, to ACE Industries, II'ncorporated, New York, N. Y., a corporation of New ersey Application October 23, 1952, Serial No. 316,474

2 Claims. (Cl. 137-423) This invention relates to carburetors for internal combustion engines, particularly of the automotive type, and consists in novel means for improving the operation of constant level mechanisms of the type involving multiple floats, in case of surging of the fuel or tilting of the carburetor.

Where the carburetor fuel inlet valve is controlled by a pair of floats rigidly connected together as shown, for instance, in Patent No. 2,748,796 to Joseph Schweiss, there is a tendency for the admission of excess fuel to the bowl in case the fuel level is shifted from the horizontal or its normal position of rest within the fuel bowl by surging or tilting of the carburetor. This is due to the fact that in such case, one float is held above its normal operating position with relation to the surface of the fuel and, therefore, applies its weight to the other float which, consequently, is immersed more deeply than normal into the fuel. The above mentioned copending application suggests a different solution of this problem.

According to the present invention, this problem is solved by the provision of independently pivoted floats, both of which normally actuate the fuel inlet valve to maintain a substantially constant level fuel within the bowl, but either of which may, independently, actuate the needle valve, in case of tilting or surging.

In the accompanying drawings which illustrate the invention:

Fig. 1 is an elevation, mostly taken in vertical transverse section, ilustrating an automotive carburetor embodying the invention.

Fig. 2 is a substantially enlarged detail in perspective showing the float pivoting and needle valve actuating parts.

Fig. 3 is a side view of the parts in Fig. 2, but showing one float arm dropped from its normal position.

Fig. 4 is a somewhat diagrammatic view showing the float structure disassembled and illustrating the independent operation of the floats.

Fig. 5 is an enlarged top view of the detail structure in Figs. 2 and 3.

Fig. 6 is a lower end view of the detail in Fig. 5.

The carburetor in Fig. 1 includes a downdraft mixture conduit 8 having a butterfly throttle valve 9 in the lower part thereof on an operating shaft 10. In the upper part of the mixture conduit is the usual choke valve (not shown) controlled by automatic choke mechanism of any known form in a housing 11.

Surrounding the mixture conduit is the float bowl structure, substantially as illustrated in the above mentioned copending application, and having enlarged portions, as at 12, at opposite sides of the mixture conduit, and connecting portions as at 13 and 14. At the bottom of bowl portion 14 is a main metering orifice element 15 controlled by metering pin 16 operated in any suitable way and leading to upwardly inclined main fuel passage 17 supplying fuel to main nozzle 18 and idling system 19, 20, and 21, as is well known.

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A threaded fuel inlet connection 22 is formed on the bowl cover structure 23 above the connecting portion 13 and receives a filtering screen 24 and an inlet valve seat element 25 and needle valve 26 controlling the admission of fuel to the bowl structure. The needle valve, in turn, is controlled by dual float structure as illustrated in Figs. 2'6, including identical floats 27 and 28 havingarms 29 and 30 projecting therefrom and terminating in bracket portions 31 and 32, each with a pair of ears 33 and 34 and 35 and 36, journalled on a pivot pin 37 which, itself, is journalled in the side walls of connecting bowl portion 13.

A needle valve actuating lip or shelf element 38, normally resting on bracket portions 31 and 32, has a pair of loops 39 and 40 rotatably received on pin 37 between each pair of bracket ears 33, 34, 35, and 36 so as to maintain the bracket portions of the float arms properly assembled on the pin. In normal assembly, needle valve 26 rests upon and is directly actuated by the shelf element, a pair of upstanding lugs 41, 42, on the shelf element adjacent loops 39 and 40 normally extends to the left of needle seat element 25, as viewed in Fig. 1, so as to abut this latter element to limit the clockwise rotation of the shelf element. A pair of depending, angular feet 43 and 44 on the shelf element depend through recesses 45 and 46 in the bracket portions of the float arms and underlie these bracket portions so as to limit the clockwise rotation of the float arms and dropping of the floats in case the bowl cover is removed from the carburetor. The floats and needle valve can be disassembled, of course, upon withdrawal of pin 37. A slot 47a between fingers 47 serves to accommodate a needle valve retaining clip (not shown).

Figs. 3, 4, and 6 illustrate how the individual floats 27 and 28 are free to seek their own levels in their respective fuel bowl parts. During normal operation, bracket portions 31 and 32 of the float arms both underlie and support shelf element 38, as in Fig. 2, and, together, actuate needle valve 26 so as to admit suflicient fuel to maintain the fuel within the bowl at a substantially constant level. When the floats are at diflerent levels, as in Fig. 4, representing a fuel surge condition caused for instance, by sudden stopping of the vehicle, only the higher float supports actuate the needle valve, and the other float hangs free thereof.

In operation, particularly in case of surging of the fuel, as represented by the broken line YY in Fig. 4, which has the effect of lifting one float 27 above the other, the higher float, alone, will remain in engagement with needle valve actuating shelf element 38 and, at least for the moment, will constitute the sole control of the inlet needle valve. In Fig. 4, and in detail Figs. 3 and 6, one float 27 is shown as constituting the needle valve control while the other float 28 has rotated clockwise relative to the pivot pin so that its journaled bracket support is out of engagement with valve actuating shelf 38 and, of course, the free float does not aifect the buoyancy of the momentarily operating float 28.

Accordingly, the excessive immersion or depression of the relatively higher float, as in case of rigidly connected floats, is avoided as is the resulting excessive supply of fuel to the fuel bowl.

The exact arrangement of the floats or float parts, including the manner of support and the disposition of the floats within the bowl, and the number of floats, may be modified. Also, the bridging shelf part 38 may be attached to the needle valve or a part thereof, instead of being separate. These and other modifications as will occur to those skilled in the art, may be made without departing from the spirit of the invention, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

What is claimed is:

1. Carburetor constant level bowl structure comprising pair of float port and posishelf element shelf element opping-Ofsaid t loss of said tingv structure 1: members to 

